Android - Firefox & Chrome close-tab behavior. Want to change some settings but what?

[PianoPlayer88Key]

Hey... I'd like to figure out how to change some behavior in Chrome & Firefox on Android when I close tabs.  

 

A video demonstrating a few examples is at 

 

 

I'll paste text from the description here...

 

A.  In both Firefox and Chrome, when you use back button to close a tab, if the originating tab is still open it switches to that tab.

B.  In Firefox, if the originating tab was closed, it goes to the home / overview / new tab page, but the tab is still open in the background.

C   In Chrome, if the originating tab was closed, it goes to the next (previous) tab in the strip.

D.  However, if you close Chrome (or it crashes or device restarts), then tapping back button from an open tab exits from the app.

E.  In Firefox, closing and reopening the browser doesn't change the behavior.

F.  Basically what I want to set up is: have both browsers, regardless of whether they've been restarted, behave like Chrome does in C.

Sorry for no timestamps (in the video), I'm posting this from my phone and there are things you just can't do on this (or are extremely inefficient) that you can do on a PC.
(That irks me to no end, that a phone makes it hard to, or won't even let you, do things that can be easily done on a PC with less RAM, a slower CPU & GPU, and a lower resolution screen.  That's a topic for another time / post though.)

 

Also I had to pause posting this to drive for a bit, and now I can't remember if I'm posting in the correct (programs, apps, websites) subforum, and the mobile interface doesn't show me that info from the post screen.